Discord and FB Messenger are both free to use privately and for businesses. The offer HTML or JSON embed codes so that we may embed them into the tool. This would allow us to have a chat system that we can use to communicate with our users. It adds the button as an overlay in the bottom righ corner and is non intrusive. I added this to siberiancms in a matter of minutes by just editing a json file. I think it would be a great addition.
We have our own code component, use it